Fan structure

ABSTRACT

A fan structure includes a hub and at least one set of blades connected to and extending away from the hub, each of the blades having a plurality of steps with a height difference formed away from the periphery of the hub, the height of the inside one of the steps higher than that of the outside one of the steps, thereby providing a disturbed flow-guiding effect so as to enhance the air pressure and the air flow of the wind flow field.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fan structure, in particular, a fan structure for a heat dissipating fan.

2. Description of Related Art

A conventional fan structure generally comprises a center portion and a plurality of blades extending from the periphery of the center portion. The fan structure is further assembled with electronic parts and a frame so as to form a heat dissipating fan for dissipating all kinds of electronic devices.

However, the conventional fan structure can merely generate a vortex flow field during a rotating operation. The air pressure and the air flow of the vortex flow field cannot be effectively improved due to the shape of the blade so as to result in poor heat dissipating performance. Further, a problem of the blades also generating noises with high decibels during high speed rotation should be resolved immediately.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a fan structure having a step structure formed on the end of a blade, thereby providing a disturbed flow-guiding effect so as to enhance the air pressure and the air flow of the wind flow field. In order to achieve the above mentioned objective, the present invention provides a fan structure comprising a hub and at least one set of blades extending from the hub, each of the blades has a step structure radially formed away from the periphery of the hub.

In order to achieve the above mentioned objective, the present invention provides a fan structure comprising a hub and at least one set of blades connected to and extending away from the hub, each of the blades having a plurality of steps with a height difference formed away from the periphery of the hub, the height of the inside one of the steps higher than that of the outside one of the steps.

The present invention further has the following effect of noise suppression by forming a fillet on the tip of the outside step.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a stereoscopic diagram illustrating a fan structure according to a first embodiment of the present invention.

FIG. 2 is a stereoscopic diagram with respect to another view angle of FIG. 1.

FIG. 3 illustrates a top-view diagram with respect to FIG. 1.

FIG. 4 illustrates a sectional diagram along a line 4-4 of FIG. 3.

FIG. 5 is a schematic diagram illustrating the fan structure according to a second embodiment of the present invention assembled with a frame.

FIG. 6 is a schematic diagram illustrating the fan structure according to a third embodiment of the present invention assembled with a frame.

FIG. 7 is a schematic diagram illustrating the fan structure according to a fourth embodiment of the present invention assembled with a frame.

FIG. 8 is a schematic diagram illustrating the fan structure according to a fifth embodiment of the present invention assembled with a frame.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description and the technical contents of the present invention are illustrated with the accompanied drawings as follows. The accompanied drawings merely provide reference and description instead of a limit for the present invention.

Please referring to FIGS. 1-4, according to the embodiment, a fan structure 1 substantially comprises a hub 10 and a plurality of blades 20. The hub 10 is composed of a circular upper plate 11 and an annular shrouding plate 12 downwardly bended and extended from the edge of the upper plate 11. A shaft 13 is centrally connected to the inside of the upper plate 11 and surrounded by the shrouding plate 12.

Nine blades 20 radially extend away from the peripheral surface of the shrouding plate 12. Each blade 20 is substantially of a three dimensional arched shape, which has an upper arc surface 21 and a lower arc surface 22 correspondingly formed under the upper arc surface 21. Additionally, the cutting line of the upper arc surface 21 intersects with the axle line of the hub 10 (i.e., an axial-flow type blade). Each blade 20 has a step structure 30 radially formed away from the edge of the hub 10. The step structure 30 is consisting of an inside step 31 and an outside step 32. In addition, a height drop is formed between either the steps 31, 32 or the step 31, 32 and the upper arc surface 21. The height of the inside step 31 is lower than that of the upper arc surface 21 while being higher than that of the outside step 32. Further, a fillet 321 for noise suppression is formed above the tip of the outside step 32.

Furthermore, each blade 20 may be formed either by directly extending from the edge of the hub 10 or by being linked to the peripheral surface of the hub 10 via a connecting method and extending away from the hub 10.

In the utilization of the high speed operation of the fan structure 1, each blade 20 sucks air from the back thereof and push the air forward via the upper arc surface 21. Such air will be blowed out in the form of vortex flow. The air pressure and the air flow may be enhanced by disposing the step structure 30 on the tip of the blade 20 which can alter said vortex flow field and provide a disturbed flow-guiding effect.

Please referring to FIG. 5, which illustrates the fan structure according to the second embodiment of the present invention, the fan structure 1 a differs from the fan structure 1 according to the first embodiment in that the fan structure 1 a is substantially combined with a frame 5. According to the embodiment, the blades comprises three blades 20 with the step structure 30 and six blades 20 a without the step structure 30. The three blades 20 commonly form one set and are uniformly disposed between the blades 20 a.

Please referring to FIG. 6, which illustrates the fan structure according to the third embodiment of the present invention, the blades comprises six blades 20 with the step structure 30 and three blades 20 b without the step structure 30. The six blades 20 commonly form three sets and are uniformly disposed between the blades 20.

Please referring to FIG. 7, which illustrates the fan structure according to the fourth embodiment of the present invention, the blades comprises three blades 20 with the step structure 30 and three blades 20 c without the step structure 30. The three blades 20 commonly form one set and each is uniformly disposed between any two adjacent blades 20 c.

Please referring to FIG. 8, which illustrates the fan structure according to the fifth embodiment of the present invention, the blades comprises two blades 20 with the step structure 30 and six blades 20 d without the step structure 30. The two blades 20 commonly form one set and each is uniformly disposed between any two adjacent blades 20 d.

In conclusion, the fan structure according to the present invention indeed achieve the purpose and thus solves the defect of the prior art. Further, it totally complies with requirements for the application of an Utility patent extremely based on the novelty and nonobviousness thereof such that an application is filed pursuant to the Patent Law. Applicant respectfully requests an examination for the application so as to protect the invention of the inventor. 

What is claimed is:
 1. A fan structure, comprising: a hub; and at least one set of blades, extending from the hub, each of the blades having a step structure radially formed away from the periphery of the hub.
 2. The fan structure of claim 1, wherein the set of blades is consisting of two blades.
 3. The fan structure of claim 1, wherein the set of blades is consisting of three blades.
 4. The fan structure of claim 1, wherein the hub includes an upper plate and a shrouding plate bended and extending from the periphery of the upper plate, the set of blades extending from the shrouding plate, respectively.
 5. The fan structure of claim 4, further comprising a shaft centrally connected to an inside portion of the upper plate and surrounded by the shrouding plate.
 6. The fan structure of claim 1, wherein the step structure has a fillet formed on the tip thereof.
 7. A fan structure, comprising: a hub; and at least one set of blades connected to and extending away from the hub, each of the blades having a plurality of steps, the steps having a height difference and formed away from the periphery of the hub, a height of an inside one of the steps higher than a height of an outside one of the steps.
 8. The fan structure of claim 7, wherein the set of blades is consisting of two blades.
 9. The fan structure of claim 7, wherein the set of blades is consisting of three blades.
 10. The fan structure of claim 7, wherein the hub includes an upper plate and a shrouding plate bended and extending from the periphery of the upper plate, the set of blades extending from the shrouding plate, respectively.
 11. The fan structure of claim 10, further comprising a shaft centrally connected to the inside of the upper plate and surrounded by the shrouding plate.
 12. The fan structure of claim 7, wherein each of the blades has an upper arc surface and a lower arc surface correspondingly formed under the upper arc surface, a cutting line of the upper arc surface intersecting with an axle line of the hub.
 13. The fan structure of claim 12, wherein the inside one of the steps is disposed between the upper arc surface and the outside one of the steps, and the height of the inside step is lower than that of the upper arc surface.
 14. The fan structure of claim 7, wherein the outside step has a fillet formed on the tip thereof. 